Illumination Engineering Lecture Note

Illumination engineering is a field that spans many topics, including the development of sources, design of luminaires and light pipes, measurement of lighting conditions, and machine vision. The number of industries actively working in the field of illumination is also expansive, including: automotive, displays, general lighting, consumer, lithography, architecture, and bio-optics. Current sectors driving the envelope of illumination engineering include solid-state lighting, liquid crystal on silicon displays, photovoltaic, organic LED displays, day lighting, energy efficiency, and biomedical applications of lighting.

The previous paragraph illustrates how pervasive illumination engineering is in our daily lives. We depend on lighting in order to function: from lighting our offices to illuminating the roads for nighttime driving to illuminating the displays of the computers on which we depend so heavily. The two most common factors in illumination system design are efficiency and uniformity of the distribution. In regards to efficiency, Table 1 shows the 2004 United States Department of Energy review of British thermal units (Btu) consumption to provide lighting for the residential and commercial sectors in 1990 and 2002 and the projected amounts for 2010 and 2025.¹ Note that this table does not include expenditures in the transportation and industrial sectors. Also, it is only for lighting of our homes and workplaces, and does not include a number of other illumination costs, including displays, indicator lights on appliances, or associated costs for cooling due to heat generation by our lights. Including all such costs, it has been speculated that lighting leads to about 25 of our yearly energy expenditures. Reference 1 indicates that lighting consumption and its reduction is expected to be the primary focus for the commercial sector until 2025. New technologies such as day lighting and solid-state lighting will lead to more efficient use of energy in the future.